Michael Douglas has revealed that his stage 4 throat cancer was the result of an HPV infection that he got from oral sex. In an interview with the Guardian last Sunday, the 68-year-old actor was asked whether he regretted smoking and drinking, both of which are linked to throat cancer. He answered, “No. Because, without wanting to get too specific, this particular cancer is caused by HPV [human papillomavirus], which actually comes about from cunnilingus.”

About 14,000 throat cancers are diagnosed every year in the US, and about 70 percent of those are related to HPV, the virus most known for causing cervical cancer and anal cancer.

Such throat cancers were far less common 15 years ago, said Dr. Robert Haddad, chief of the center for head and neck oncology at the Dana-Farber Cancer Institute; now, he said, his clinic is “packed with patients” in their 40s and 50s with HPV-related cancers.

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“They never smoked, don’t have heavy alcohol use, and often have young children,” he said, which makes it a particularly devastating diagnosis for couples.

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Often these cancers aren’t diagnosed until they’ve progressed to surrounding lymph nodes making them harder to cure, but they have a better long-term survival rate compared to those throat cancers triggered by smoking or alcohol use.

Researchers haven’t determined the reason for the quick rise in HPV throat cancers, but it may have something to do with a shift in cultural norms toward more promiscuity when it comes to oral sex or a genetic alteration in the virus that has enabled it to multiply and grow on oral tissue.

Most oral cancers linked to the virus occur on the tonsils or base of the tongue and are caused by the strain HPV-16. The HPV vaccines, Gardasil and Cervarix, protect against this strain and a wider acceptance of the vaccine in children could lead to a decline in this cancer incidence down the road.

“My husband would have gladly had a vaccine when he was 10 if he could have avoided this cancer as an adult,” said Lucy Simotes, whose husband, Tony, was treated at Dana-Farber three years ago when he was 58 for an HPV-related throat cancer. “He had radiation and chemotherapy and was on a feeding tube for 10 months,” she added, because he was unable to swallow food due to side effects from his treatments.

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Simotes, who lives in the Berkshires with her husband, worried that she herself might carry the sexually transmitted virus and opted to participate in a study led by Johns Hopkins researchers to study how often the virus gets transmitted orally in long-term partners.

“Spouses of my patients frequently ask me whether they’ll get the cancer too,” said Haddad, who was one of the coauthors of the study. The findings, presented over the weekend at the American Society of Clinical Oncology Annual Meeting, determined that only 7 percent of those whose partners have HPV-related throat cancers had HPV virus that was detected on a throat rinse test.

“We were able to show that spouses and partners of those with these kinds of cancers don’t necessarily have an increased risk of cancer themselves,” Haddad said. “They likely clear the virus from their system.”

Simotes didn’t find out whether she carried the virus, but she says she’s on a mission to make people aware of the benefits of the HPV vaccine. The Centers for Disease Control and Prevention recommends that preteen girls and boys get vaccinated; those playing catchup can get vaccinated through age 26, if they’re a woman, or age 21, if they’re a man.

Only two-thirds of Massachusetts girls ages 13 to 17 have received one dose of the HPV vaccine, according to the latest statistics, and just 47 percent have received all three doses required to give full protection against the virus. For boys, the rates are likely lower since the vaccine was only first recommended for them two years ago.

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Boston University researchers recently demonstrated that inoculation rates in two clinics could be raised by teaching pediatricians to place as much emphasis on the importance of the HPV vaccine in their discussions with parents as they do on other immunizations that are required for school entry.